Improve the resolution of the menu item homescreen launch source metric.

chrome/browser/android/shortcut_info.h

Index: chrome/browser/android/shortcut_info.h
diff --git a/chrome/browser/android/shortcut_info.h b/chrome/browser/android/shortcut_info.h
index af89f0827a2eaee210ffcf257559bf1ab9e7c24f..8c6a25f3da1cb60ffc4a43ffba4dbd3bf358a688 100644
--- a/chrome/browser/android/shortcut_info.h
+++ b/chrome/browser/android/shortcut_info.h
@@ -24,12 +24,15 @@ struct ShortcutInfo {
   // GENERATED_JAVA_CLASS_NAME_OVERRIDE: ShortcutSource
   enum Source {
     SOURCE_UNKNOWN = 0,
-    SOURCE_ADD_TO_HOMESCREEN = 1,
+    SOURCE_ADD_TO_HOMESCREEN_DEPRECATED = 1,
     SOURCE_APP_BANNER = 2,
     SOURCE_BOOKMARK_NAVIGATOR_WIDGET = 3,
     SOURCE_BOOKMARK_SHORTCUT_WIDGET = 4,
     SOURCE_NOTIFICATION = 5,
-    SOURCE_COUNT = 6
+    SOURCE_ADD_TO_HOMESCREEN_PWA = 6,
+    SOURCE_ADD_TO_HOMESCREEN_STANDALONE = 7,
+    SOURCE_ADD_TO_HOMESCREEN_SHORTCUT = 8,
+    SOURCE_COUNT = 9
   };
 
   explicit ShortcutInfo(const GURL& shortcut_url);